Air-conditioning method and apparatus



Oct. 31, 1933. J. H. DAVIS ET AL 4 1,932,513

AIR CONDITIONfNG METHOD AND APPARATiJS Filed July 18, 1931 vvzm f Inventgrs Patented Oct. 31, 1933 UNITED STATES AIR-CONDITIONING METHOD AND APPARATUS Jess 11. Davis, Baltimore, Md., and Samuel M.

Anderson, Sharon, Mass,

assignors to B. F.

Sturtevant Company, Boston, Mass, a corporation of Massachusetts Application July 18, 1931. Serial No. 551,614

Claims. (Cl. 62-117) The present invention relates to air conditioning methods and apparatus and more especially to methods and apparatus particularly adapted for conditioning the air of passenger vehicles,

, 5 such as railway cars.

In the conditioning of air of passenger cars, the desired cooling effect is commonly secured by means of electrically driven refrigeration apparatus through the medium of water or other it liquid maintained at a relatively low temperature.

The necessary current for such apparatus isobtained from an axle driven generator without storage battery, the power requirements being so heavy as normally to prohibit the use of such equipment. As a consequence, when the car slows down to a predetermined minimum speed, or stands in a station, the refrigerating apparatus becomes and remains inoperative.

It is the object of the present invention to provide a method and apparatus whereby during such low speeds or standing at stations, the cooling of the airwill be continued so long as the water or other liquid is capable of producing any appreciable reduction of the temperature, but upon the warming of the water, the transfer of heat from the water to the air will automatically be perevented so that heating of the air from the water will be impossible.

It is a further object to so construct and'opcrate such apparatus that upon the cars again exceeding such minimum speed, the water will automatically become capable once more of absorbing heat from the air to cool the same.

To the above ends, the invention consists of a method and apparatus wherein the air is cooled by means of circulating water or other fluid in turn cooled by an intermittently driven refrigerating apparatus, the circulation of the cooling water being continued for a time after the re- 40 frigerating apparatus has ceased to operate, automatically ceasing when the water becomes warm, and being resumed upon the refrigerating apparatus again becoming operative. I

- In the accompanying drawing is shown, somewhat diagrammatically, the preierred Iorm of the present invention.

The illustrated embodiment of the invention comprises a fluid circulating air conditioning system including a spray device or a dehumidiher 2, of any usual or preferred form, through which air to be conditioned is continuously forced by a fan a The conditioned air leaving the dehumidifier is distributed through a duct 6, in

any suitable manner, to different parts of the vehicle. The operation of the dehumidifier, and

the flow of air therethrough, may be controlled by any suitable instruments sensitive to temperature and humidity conditions in the vehicle. Water, which constitutes the air conditioning medium, is continuously circulated through the spray device by a pump 8. The outlet of the pump connects through a cooler 10 with the spray device and the outlet of the spray, device leads to the inlet of the pump.

The water circulated through the spray device is cooled in the cooler 10 by a refrigeration apparatus indicated diagrammatically by the compressor 11 driven by the motor 12 and the condenser 13. The refrigerant is circulated through the pipe lines 14 through the compressor, the con- 7 denser and the cooler. The refrigerator motor 12 is supplied with electric current by a generator 16 driven from the axle 18 of the vehicle through suitable gearing l9 and connected with the motor by leads 20.

The pump' 8 for circulating the water is driven by an electric motor 22 which is energized by a battery 24. The battery may be continuously charged when the vehicle is in motion by an axle generator, not shown. The drive for the g0 pump 8 being independent of the refrigerator drive, the pump will continue to operate when the vehicle is stationary. Therefore, for a short stop, even though the refrigerator is inactive, the temperature of the circulating water may be maintained sufficiently low for a considerable period and will be circulated to the spray nozzles to cool and dehumidify the air.

However, if the stop is an extended one, the temperature of the circulating water increases so that eventually it becomes ineffective for proper conditioning of the air, and if continued to be sprayed. into the air, will increase, the temperature and humidity. In order to stop the water spray under these conditions, there is placed in the circulating line a thermostat, indicated generally at 26, controlling a switch 28. This switch is maintained closed below a predetermined temperature of the spray water, but is caused to open by the action of the thermostat when the 100 water temperature rises to a predetermined value. The switch 28 is included in a relay circuit which also includes a relay coil 30 and a battery 32. If desired, a single battery may be used in' place ofthe twobatteries 24 and 32. The coil 30 normally maintains closed the stopping relay switch 34 which is connected in a lead between the battery 24 and the pump motor 22. A spring 36 tends .to open the switch 34 when the coil 30 is de-energized. Upon an extended stop, therefore, '110.

when the refrigerator is inactive, the pump 8 continues to operate until the water temperature rises above the predetermined value for which the thermostat 26 is set, whereupon the switch 34 is opened and the pump is stopped.

With the parts thus far described, it will be noted that upon resumption of operation of the refrigerator, the pump, if already stopped by the opening of the relay switch 34, would have no tendency to start because the thermostatic switch 28 will not close until cooled fluid is circulated in the circulating system. In order to provide for the automatic restartingof the circulating system, regardless of the water temperature, a second or starting relay'switch, 38 is connected in parallel to the switch 34. The switch 38 is adapted to be held open by a spring 40 but is normally held closed when thevehicle is in motion by a relay magnet 42 connected in one of the leads 20 between the axle generator 16 and the refrigerator motor 12. Although the starting switch 38 is open when the car is stationary, it is closed immediately upon restarting of the car. The closure of the switch 38 completes the circuit of the motor 22, thereby starting the pump 8 even though the stopping switch 34 remains open because of the elevated temperature of the water. After a short time, however, the water becomes sumciently cooled by the action of the'refrigerator to effect closing of the switch 34, thereby again placing the system in readiness for operation onthe reserve of cooled water at a subsequent stop.

It will be seen that the circulation of water is maintained when either of the relay switches is closed and is shut off only when both switches are open; in other words, circulation is maintained either when the water temperature is sufficiently low or when the refrigerator is active, but is stopped only under the dual condition of high temperature of the water and inactivity of the refrigerator.

Although the preferred form of the invention has been illustrated and described, the invention is not to be considered as limited to the precise construction herein shown, but may be modified within the scope of the appended claims.

Having thus described the invention, what is claimed is:

1. Air conditioning apparatus for vehicles having, in combination, a refrigeratorymeans for driving the refrigerator, an independently driven liquid circulating system to permit continued operation thereof after cessation of operation of the refrigerator, means for cooling the liquid by the refrigerator, temperature controlled means for shutting off circulation of the liquid when the refrigerator is inoperative and the temperature of the liquid rises to a predetermined value,

and means for restarting operation of the liquid' circulating system on resumption of operation of the refrigerator.

2. Air conditioning apparatus for vehicles having, in combination, a refrigerator, means for driving the refrigerator from the motion of the vehicle, an independently driven liquid circulating system to permit continued operation thereof after cessation of operation of the refrigerator by stopping of the vehicle, means for cooling the circulating liquid by the refrigerator, temperature controlled means for shutting ofl circulation of the liquid when the refrigerator is inoperative and the temperature of the liquid rises to a predetermined value, and means for restarting the operation of the liquid circulating system on resum tion of operation of the refrigerator.

3. Air conditioning apparatus for vehicles having, in combination, a refrigerator, means for driving the refrigerator, anindependently driven liquid circulating system to permit continued operation thereof after cessation of operation of the refrigerator, the fluid circulating system including a. dehumidifier and a cooler, a connection between the refrigerator and the cooler, temperature controlled means for shutting off circulation of the liquid when the refrigerator is inoperative and the temperature of the liquid rises to a predetermined value, and means for restarting operation of the liquid circulating system on resumption of operation of the refrig erator.

having, in combination, a refrigerator, means for driving the refrigerator from the motion of the vehicle, an independently driven liquid circulating system to permit continued operation thereof after cessation of operation of the refrigerator by stopping of the vehicle, the liquid circulating system including a dehumidifier and a cooler, a connection between the refrigerator and the cooler, temperature controlled means for shutting off circulation of the liquid when the refrigerator is inoperative and the temperature of the liquid rises to a predetermined value, and means for restarting operation of the liquid circulating system on resumption of operation of the refrigerator.

5. Air conditioning apparatus for vehicles having, in combination, a refrigerator, means for driving the refrigerator, an independently driven fluid circulating system to permit continued operation thereof after cessation of operation of the refrigerator, the fluid circulating system including a dehumidifier and a cooler, a connection from the refrigerator to the cooler, and means for stopping circulation of the fluid when the refrigerator is inactive and the temperature of the cooling fluid medium is above a predetermined value.

6. Air conditioning apparatus for vehicles having, in combination, a refrigerator, means for driving the refrigerator, an independently driven liquid circulating system to permit continued operation thereof after cessation of operation of the refrigerator, the liquid circulating system including a-dehumidifier and a cooler, a connection from the refrigerator to the cooler, thermostatic means in the circulating, system, and means for operating the circulating system either during the operation of the refrigerator or by the presence of liquid at lower than a prein the circulating a drive for said circulating means independent of the axle driven means to permit continued circulation of the liquid after stopping of the vehicle, means for stopping circulation of the liquid when the refrigerator is inoperative and upon rise of the temperature of the liquid to a predetermined value, and means for restarting circulation of the liquid upon restarting of the vehicle.

8. Air conditioning apparatus for vehicles having; in combination, a refrigerator having an electric motor, an axle driven generator, electrical connections between the generator and the motor, a cooler cooled by therefrigerator, means for circulating a fluid through the cooler, means for conditioning air .with the circulated fluid, an electric motor drive for the circulating means, a motor circuit-including a source of electrical energy for said electric motor. drive independent of said axle driven generator, a thermostatically controlled switch to close the motor circuit upon the circulation of fluid below a predetermined temperature,and a switch operated by the generator to close the motor circuit when the generator is running.

9. Air conditioning apparatus for vehicles having, in combination, a refrigerator having an electric motor, an axle driven generator, electrical connections between the generator and the motor, a cooler cooled by the refrigerator,

' means for circulating a liquid through the cooler,

. means for conditioning air withthe circulated liquid, an electric motor drive for the circulating means, a motor circuit including a source of electrical energy for said electric motor drive independent of'said axle driven generator, two

parallel switches in the motor circuit, means,

for opening one of said switches when the temperature of the circulated liquid rises to a predetermined value, and means for opening the other of said switches upon stopping of the vehicle.

10. Air conditioning apparatus for vehicleshaving, in combination, a refrigerator having an electric motor, an axledriven generator, electrical connections between the generator and the motor, a cooler cooled by the refrigerator, means for circulating a liquid through the cooler, means for conditioning air with the circulated liquid, an electric motor drive for the circulating means, a motor circuit including a source of electrical energy for said electric motor drive ins dependent of said axle driven generator, arelay controlled by the temperature of the circulated liquid and having a switch in the motor circuit,

and a second relay controlled by the axle driven ,controlled devices for shutting off the circulation generator and-having a switch in the motor circuit in parallel to said temperature controlled switch.

11. Air conditioning apparatus .for vehicles having, in combination, an axle driven refrig erator, a cooler cooled by the refrigerator, a fluid circulating system including the cooler, an electric motor drive for the circulating system, two parallel switches for controlling the electric motor drive; means for opening. one of the switches when the temperature of the fluid rises above a predetermined value, and means for opening the other switch upon stopping of the vehicle. 7

- 12. A method of conditioning air for a vehicle having an axle driven refrigerator which consists in continuously irculating a liquid in heat exchange relationshi with the air, cooling the liquid by the refrigerator, stopping the circulation of the liquid upon rise of the liquidto a predetermined temperature when the vehicle is stationary, and resuming circulationof the liquid upon restarting of the vehicle.

18. Air conditioning apparatus having, in com-' bination, a liquid circulatory system, refrigerating means for cooling the liquid in the system, means .operating independently of the operation of the refrigerating means for causing circulation of the liquid in the system, and temperature .determined temperature.

of the liquid when the refrigerating means are inoperative and the temperature of the liquid rises to a predetermined value. 7

14. Air conditioning apparatus having, in combination, a liquid circulatory system, refrigerating means for cooling the liquid in the system,- means for causing circulation of the liquid in the system, and control devices for throwing said liquid circulating means out of operation when the liquid rises to a predetermined temperature following a cessation of the operation of the refrigerating means and for throwing said liquid circulating means intooperation upon a resumption of the operation of the refrigerating means.

15. Air conditioning apparatus having, in combinatioh, a liquid circulatory system, intermittently operating refrigerating means for cooling the liquid, means for causing circulation of the liquid in the system, and devices for maintaining the liquid circulating means in operation while the refrigerating meansare -in operation and for continuing said liquid circulating means in operation after the refrigerating means have become inoperative and until the liquid rises to a pre- 18. Air conditioning apparatus having, in combination,a liquid circulatory. system, intermittently operating refrigerating means for cooling the liquid, a pump for causing circulation of the liquid in the system, a motor for the pump, and a motor switch thermostatically controlled by the temperature of the liquid in the system for stopping the operation of the pump motor when the liquid rises to a predetermined temperature.

17. A method of conditioning air which consists in circulating a liquid in heat exchange relationship with the air, intermittently cooling the liquid, continuing the circulation of the liquid after the cooling has stopped and until the liquid rises to a predetermined temperat e, and then stopping 1 5 the circulation. v

18. A method of conditioning air which consists in circulating a liquid in heat exchange relationship with the air, intermittently cooling the liquid,

19. Air conditioning apparatus having, in com- 5 bination, a cooler in heat exchange relationship with air, means for supplying the cooler with cooling medium, said means including a compressor driven from the motion of the vehicle, and a temperature controlled devices for controlling the supply of cooling medium to the cooler operating to continue such supply after the cessation of operation of the compressor by stopping of the vehicle and to cut on? such supply when the temperature of the medium rises to a predetermined point.

20. A method of conditioning air which consists, in circulating a cooling medium in heat exchange relationship with the air, intermittently absorbculation of the medium after. the absorbing of the heat therefrom has stopped and until the medium rises to a predetermined temperature, then stopping the circulation. and resuming the circulation of the medium when the absorbing of the heat therefrom is resumed.

- JESSE H. DAVIS.

SAMUEL M. ANDERSON. 

